patchupdate.py: Add '--version' command to show staging/wine version.

debian/tools/patchinstall.sh.in

@@ -36,6 +36,7 @@ usage()
 	echo "  --help               Display this help and exit"
 	echo "  --no-patchlist       Do not apply patchlist (needed for 'wine --patches')"
 	echo "  --no-autoconf        Do not run autoreconf and tools/make_requests"
+	echo "  --version            Show version information"
 	echo "  -W patchset          Exclude a specific patchset"
 	echo ""
 	echo "Backends:"
@@ -47,6 +48,17 @@ usage()
 	echo ""
 }}
 
+# Show version information
+version()
+{{
+	echo "Wine Staging {latest_staging_version}"
+	echo "Copyright (C) 2014-2015 the Wine Staging project authors."
+	echo ""
+	echo "Patchset to be applied on upstream Wine:"
+	echo "  commit {latest_wine_commit}"
+	echo ""
+}}
+
 # Critical error, abort
 abort()
 {{
@@ -132,6 +144,11 @@ while test "$#" -gt 0; do
 			shift
 			;;
 
+		--version)
+			version
+			exit 0
+			;;
+
 		-W)
 			enable=2
 			shift